拮抗产肠毒素大肠杆菌K88的中药和益生菌的筛选及其发酵工艺优化

Screening of traditional Chinese medicine and probiotic bacteria against enterotoxigenic Escherichia coli K88 and optimization of its fermentation process

目的：筛选对产肠毒素大肠杆菌（ETEC）K88具有较好抑菌效果的中药和益生菌,以发酵前后pH值变化和活菌数变化为指标,摸索益生菌发酵中药的影响因素,确定其最佳发酵工艺,并考察发酵液抑菌活性。方法：采用牛津杯法从20味中药和8株乳酸菌中筛选抑菌性能较好的中药和益生菌;通过单因素试验方法确定其最佳发酵工艺;采用牛津杯法检测发酵液抑菌活性。结果：6味单味中药和2株益生菌对K88具有较好的抑菌效果。益生菌发酵中药的最佳发酵工艺为：乌梅、蒲公英及五倍子按比例配制,接入4%的乳酸菌种子液,初始发酵pH值为5.5,37℃发酵24 h,发酵液抑菌效果优于乳酸菌菌液和中药水提液。结论：所筛选的中药组方配比及发酵工艺为开发防治产肠毒素大肠杆菌K88所致仔猪腹泻生物制剂提供了参考。

Screening of traditional Chinese medicine and probiotics with good bacteriostatic effects on enterotoxigenic Escherichia coli（ETEC）K88.Based on the change of pH and the number of live bacteria before and after fermentation,the factors affecting the fermentation of traditional Chinese medicine were explored,the optimum fermentation technology was determined and antibacterial performance were evaluated. Method： Firstly, the traditional Chinese medicine and probiotics with better bacteriostatic performance were screened from 21 kinds of traditional Chinese medicine and 8 strains of lactic acid bacteria by the Oxford cup method.Secondly,the optimum fermentation process was determined by single factor test.Finally,the bacteriostatic performance of the fermentation broth was determined by Oxford cup method. 6 kinds of traditional Chinese medicine and 2 kinds of probiotics with better bacteriostasis effect on K88 were obtained. Result：The optimum fermentation process of traditional Chinese medicine by probiotics is as follows： The best compound admixture of Fructus Mume,Herba Taraxaci and Galla Chinensis was fermentatedby 4 % lactic acid bacteria seed liquid,the initial pH 5.5 at 37 ℃ for 24 hours. Conclusion：The compound of traditional Chinese medicine and fermentation process would provide reference for the developmentagents for preventing and controlling diarrhea of piglets caused by biological preparation for piglet diarrhea caused by enterotoxigenic Escherichia coli K88.